Metamath Proof Explorer


Theorem isstruct

Description: The property of being a structure with components in M ... N . (Contributed by Mario Carneiro, 29-Aug-2015)

Ref Expression
Assertion isstruct ⊢ F Struct M N ↔ M ∈ ℕ ∧ N ∈ ℕ ∧ M ≤ N ∧ Fun ⁡ F ∖ ∅ ∧ dom ⁡ F ⊆ M … N

Proof

Step Hyp Ref Expression
1 isstruct2 ⊢ F Struct M N ↔ M N ∈ ≤ ∩ ℕ × ℕ ∧ Fun ⁡ F ∖ ∅ ∧ dom ⁡ F ⊆ … ⁡ M N
2 df-3an ⊢ M ∈ ℕ ∧ N ∈ ℕ ∧ M ≤ N ↔ M ∈ ℕ ∧ N ∈ ℕ ∧ M ≤ N
3 brinxp2 ⊢ M ≤ ∩ ℕ × ℕ N ↔ M ∈ ℕ ∧ N ∈ ℕ ∧ M ≤ N
4 df-br ⊢ M ≤ ∩ ℕ × ℕ N ↔ M N ∈ ≤ ∩ ℕ × ℕ
5 2 3 4 3bitr2i ⊢ M ∈ ℕ ∧ N ∈ ℕ ∧ M ≤ N ↔ M N ∈ ≤ ∩ ℕ × ℕ
6 biid ⊢ Fun ⁡ F ∖ ∅ ↔ Fun ⁡ F ∖ ∅
7 df-ov ⊢ M … N = … ⁡ M N
8 7 sseq2i ⊢ dom ⁡ F ⊆ M … N ↔ dom ⁡ F ⊆ … ⁡ M N
9 5 6 8 3anbi123i ⊢ M ∈ ℕ ∧ N ∈ ℕ ∧ M ≤ N ∧ Fun ⁡ F ∖ ∅ ∧ dom ⁡ F ⊆ M … N ↔ M N ∈ ≤ ∩ ℕ × ℕ ∧ Fun ⁡ F ∖ ∅ ∧ dom ⁡ F ⊆ … ⁡ M N
10 1 9 bitr4i ⊢ F Struct M N ↔ M ∈ ℕ ∧ N ∈ ℕ ∧ M ≤ N ∧ Fun ⁡ F ∖ ∅ ∧ dom ⁡ F ⊆ M … N